The Lithology And Structure Of The Grand Teton Range Wyoming

Spencer Bennett
Dr. Field
Structural Geology 312
November 13, 2014
The Lithology and Structure of the Grand Teton Range, Wyoming
Abstract
Wyoming’s Grand Teton range has a vast variety of rock units, along with an assortment of ages and names. Along with the variety of lithology that the Teton Range has to offer it also has a unique normal fault the has down dropped Jackson Hole and up lifted the Teton range. The geological history is also quite exceptional knowing that the structure of the Grand Teton range began over 2.5 billion years ago.
Introduction
The Grand Teton area consists of some of the oldest and youngest rocks, and mountain ranges, in America. They are found in the Middle rocky Mountain physiographic province. The core

The Teton range has an elevation of 4 197.096 meters with eight peaks over 3 657.6 meters in elevation.
Lithology
Geological structures in Grand Teton National Park are found within the Middle Rocky Mountain physiographic province, and result from tectonic events associated with the Laramide orogeny. The Tetons are still affected by these events today. The Laramide orogeny is primarily responsible for bringing Precambrian metamorphic and plutonic rocks, those composing the core of the Tetons, to the surface. The Teton Range consists of a core of igneous and metamorphic Precambrian rocks overlain in most of the range by westward dipping sedimentary Paleozoic rocks. The Grand Teton Range consists of rocks ranging from the Precambrian, Paleozoic, Mesozoic, and Cenozoic time periods. The erosion-resistant Precambrian rocks comprise the highest peaks of the Teton Range and are part of the Wyoming Craton. The oldest units (>2680 Ma), observed in the north, south, and the eastern part of the central Tetons, are Archean layered gneisses, including biotite gneiss, plagioclase gneiss, amphibole gneiss, and some amphibolite (Reed and

The Tetons have been glaciated at least three times, with the oldest event being the most widespread event. These great ice masses shaped and sharpened the Tetons. Beginning 2 million years ago glaciers began to erode and sculpt the Teton Landscape. Large masses of ice flowed from the topographic high of the Yellowstone Plateau down across the valley of Jackson Hole numerous times leveling the valley floor. The present Teton landscape was established on the uplifted Teton block by alpine glaciation along deeply carved stream valleys. Several series of global cooling followed by warming over the past 2 million years resulted in the advance and retreat of alpine glaciers in the Teton